Telephone system



Feb. 28, 1928. 1,660,975

R. L. QUASS TELEPHONE SYSTEM I Filed July 19. 1926 2 Sheets-Sheet 1 CI! CIDDDQ Feb. 28, 1928.

1,660,975 R. L. QUASS 'iELEPHONE SYSTEM Filed July 19. 1926 v 2 Sheets-Sheet 2 Patented Feb. 28,1928.

UNITED STATES PATENT OFFICE. RAL PH L. Q 'UASS; OF I'TAWTHORNE. NEW JERSEY, ASSIGNOR TO BELL IEIlEPHONE LABORATORIES, INCORPORATED, OF NEW YOBK, N. Y., A CORPORATION OF NEW.

YORK.

TELEPHONE SYSTEM.

Application filed July 19, 1926. Serial No. 123,312.

The invention relates to telephone switching systems and particularly to exchange systems 'in which a plurality of selectors and a connector are used.

The principal object of the invention is to improve the operation of the selector and the coiinector switches of such systems.

Another object is an improved method of controllingthe application of ringing current. i h i It has been the practice heretofore in a connection comprising a plurality of selec tors and a connector to have each separate switch controlled directly by the calling subscribers dial and the ringing current has heretofore been controlled and connect-- i of the connector.

ed to the called subscribers station by the connector. has been controlled by a preceding selector switch.

In this invention the last two switches 0 means of the preceding switch and the ring ing is controlled by the same switch instead controlled by a second relay in said preceding selector. The relay which controls the positioning of the switches follows the dial and repeats the pulses to the following switches. The relay which controls the ringing is released by the removal oi ground from the tip of the line'when the connector has been connected to an idle line.

A more complete conception of the invention inaybe had from the following detailed description and the accompanying drawings, of which; Fig. 1 disclosesa calling line, a line finder and three selectors in schematic form, anda fourth selector in detail; Fig. 2'discloses a fifth selector, a connector, and a called subscribers station.

When subscriber 101 removes the receiver The release of the connector.

The release of the con 1 119 andrelease lnagnet 115.

'111, lower inner back contact of relay 108 over the ring of the line through the inter vening switches and the loop of station 101, back over the tip of the line, and the inter- Vening switches, upper middle back contact of relay 108, outer back contact of relay 111, resistance 13;} to ground through the right winding of relay 112. Relay 11.2 operates and closes an obvious circuit for relay 113 which in turn closes a circuit from ground 'on its'upper front contact to the uppcr inner back contact of relay 108, upper outer a plurality are controlled and positioned by a back contact of relay 110 to battery througl'r the winding ofrelay 109. With relay 10D operated the switch is now in condition for dialing. When the subscriber at station 101 operates dial 102 the circuit for relay 112 is opened, thereby releasing it and closing a circuit for operating relay 116 and magnet 117 inseries from battery through the wind ings of magnet 117 and relay 116, lower normal contact of vertical off-normal spring 126;. lower outer back contact of relay 110, lower front contact of relay 113, to ground at the back contact of relay 112. Relay 113 does not release when relay 112 opens its contacts as it is slow torelease. Relav 112 'follows'the inipulsesiroin dial 102, thereby operating and releasing magnet 117 and causing the brushes 130, 1&0 and 150 tohe stepped upward. Relay 116 does not release during these impulses as it is slow to release, thereby closing a second operating circuit tor magnet 117 through its inner front contact. The first operating circuit is opened after the first impulse has been dialed by the operation of verticalhoif-normal contact springs 126 and circuits are completed inpart for the rotary magnet The operation ofsprings 126 also closes a circuit from ground on theupper front contact of relay 118, lower outer front contact of relayllltl,

. contact of relay 118.

middle alternate contact of off-normal springs 126, back contact of rotary magnet 119 to battery through the winding of relay 118. Relay 118 operates and locks over a circuit from. battery through its winding, back contact of magnet 119, middle alternate contact of springs 126 to ground on the 1111161, front contact of relay 118. When the re uirin four-)art rin in Should brush O D U 128 come to rest on either terminal 129 or 134 a circuit is closed from battery through the winding of relay 114, brush 128, either contact 129 or 134, lower outer back contact of relay 116 to ground on the upper front Relay 114 operates and locks over a circuit from ground on the upper front contact of relay 113, upper inner hack contact of ringing cut-01f relay 108, upper inner front contact and winding of relay 114 to battery. when relay 114 is not operated, ringing current from source 123-is used but with relay 114 operated, ringing current from source 122 is used.

. Ringing current is not connected to the connection at this time as relay 109 is operated.

If the brushes in their vertical movement have come to rest on a busy trunk, ground will be found on terminal 151 and a circuit will be closed from this ground over brush 150, back contact of release magnet- 115,

lower outer front contact of relay 109, upper inner back contact of relay 110, middle alternate contact of vertical oH-normal springs 1 6, back contact of rotary magnet 119 to battery through the winding of relay 118v The release of relay 116 when the dialing was finished opened the locking circuit traced above for relay 118 but it is now held over a circuit to the busy ground. \Vith relay 1.18 operated a circuit is closed from battery through the winding of rotary magnet 119, lower front contact of relay 118, lower back contact of relay 116 to ground on the upper front contact of relay .113. The operation of rotary magnet 119 opens the operating circuit for relay 118 thereby opening the operating circuit for the rotary magnet. Should the next trunk be busy relay 118 will be reoperated and the cycle relay 118 and the brushes will come to rest.

repeated until an idle trunk is found at which time there wlll be no operation of As long as the brushes were resting on a busy terminalthe winding of relay 110 is shun-ted by the busy ground butwhen an idle trunk is reached a circuit is closed from ground on the upper front contact .of relay 113, upper inner back contact of relay 108,

winding of relay 110, middle alternate contact of off normal springs 126, back contact of magnet 119 to battery through the wind ingof relay 118. Relay 118 is marginal so does not operate in this circuit as the resist ance of relay 110 is too high but relay 110 operates and places a busy ground on the idle trunk terminals from ground on the upper front contact of relay 113, upper inner front contact of relay 110, lower outer front contact of relay 109, back contact of release magnet 115 to brush 150 thereby making the trunk selector test busy to all other selectors and close a circuit for relay 206 from battery, through its upper wind ing of innermost upper back contact, back contact of release magnet 209, terminal 151, brush 150, back contact ofrelease magnet 115 to the above mentioned ground.

Relay 206 only operates partially at this time. It is so adjusted that'only contact 203 is opened while the other contacts remain normal. The 'openin'g'of contact 208 prevents release magnet 209 from being energized when the switch isstepped off-normal. No circuit is closed at this time through the lower winding of relay 206. A circuit is now closed from ground on the back contact of relay 112, lower front contact of relay 113, lower outer front contact of relay 110, brush 140, terminal. 141, back contact of armature 204 of relay 206, normal contact of vertical off-normal spring 214, winding of relay 208 to battery through the winding of vertical magnet 211. Relay 208 operates and locks to ground from relay 112 through its lower front contact and opens at its upper back contact a possible circuit for rotary magnet 212. Selector 200 is now in position for receiving the impulses from dial 102.

Belay 1.12 follows the impulses as before and transmits the first impulse over the circuit traced above to vertical magnet 211. The remaining impulses are transmitted through the lower front contact and winding ofre lay 208 and a circuit is closed from ground on the upper front contact of relay 208 to shunt the lower winding of relay 206. When the brushes start upward the vertical olfnormal springs 214 are o )erat-ed thereby closing a circuit from ground on the upper front contact of relay 208, middle alternate contact of off-normal spring 214, back contact of rotary magnet 212, to battery through the winding of relay 207. Relay 207 operates and prepares in part a circuit for rotary magnet 212 which is not closed until relay 208 releases at the end of the dialing of the fifth digit. When relay 208 releases the circuit'for rotaryma'gnet 212 is com pleted at the upper back contact of relay 208 to ground causing the rotary magnet 212 to take one step to bring the brushes 210, 220 and 280 on the terminals of the first trunk in the selectiye level, en the operation of magnet 212 the circuit for relay 207 ,is

opened at the armature and backcontact of magnet 212- causing relay .207 -to release. When the rotary magnet 212 releases and if the brushes 210, 220 and 230 are now resting on the terminals of a busy trunk, a circuit is closed from ground onbrush 230 back a contact of armature 205 of relay 206, middle of relay 206, but if it is prematurely renewed locking ground is" provided throughthe upper armature and first contact of relay 207 The busy ground on brush 230 normally keeps the lower winding of relay 206 shunted through the back contact of armature205 the ground at the armature and front contact of relay207 will insure this shunting sleeve and the above circuit will again be closed for relay207 which will reoperateand close the circuit for magnetj2l2, causing the switch to rotate one step further. This operation Will be, repeated until an idletrunk is found.

and that brushes 210, 220 and 230 areirest we will consider that connector 250 is idle ing on its terminals. There being no ground on brush 280, relay 207 does not reoperate and the shuntaround the lower winding of relay 206 is removed." A circuit is now closed fromgroundnut-he upper front contact of relay 113, upper inner front contact of 1.10, lower outer? front contact of relay 109, back contact of release qmagnet115, brush 150, terminal 151, back contact of renet 212' to loattery through the winding of lease magnet 209, lowerwinding of relay 206,

middle alternate contact of vertical off-normal spring 214, back contact of rotary magrelay 207. Relay 207 doesnot operateat this time as it is marginal-and the resistance of the lower winding 10f relay:206 is too r 1 high. Relay 206, however, operates an connects the conductors from terminals 131. 141

andlfi]. through to brushes 210, 220 and 23 A circuit is now closed for relay 251 from the above traced ground OII'bILISll 150, terminala151, back contact of release magnet 209, front contact ofarmatnre-205 of relay j 206, brush 230, middle and lower windings of relayf251 in series to battery. Relay is so adjuste th t it only operates a sutlicientamount to-open contact 262 thereby opening a possible circuit for release magnet from battery, through thewinding of said 256. y A circuit is also closed for relay "relay, normal contact of rotary; off-normal springv 261 to the "ground above traced over brush 230. 1 Relay 252 closes a circuit for vertical magnet 258 from ground on the back contact of relay 112, over the ring of the connection as traced before, upper middle "back contactof relay 251, upper front contact of relay 252, C(Dltilt't-Qtitl of vertical otfnormal springs 255 to battery, through the windings of relay 257 and vertical. magnet 258. Relay252 also connects ground from of relay 257. This circuitmay be traced until magnet 212 operates. If the next trunk is busy ground will be found on its from ground. on the back contact of relay 112 over the ring of the connection, upper middle back contact ofrelay 251, upper front contact of relay 252, upper middle alternate contact of off-normal springs 255, front contact of relay 257 tocbat-tery, through windings of relay Y257 and magnet 258. Relay a i 257 is slow to release so does not release between impulses; After the last impulse, re-

lay 257 and magnet 258 release and the connector 250 is now in condition to receive the impulses due to the dialing of the seventh operated closes a holding circuit for relay 1 252 during the stopping of magnet 259 as the original circuit for relay 252 opened at the rotary off-normal contact 261 after the first rotary step. ,1 Relay 252 will remain operated n ntiljafter the last rotary impulse has been Idialed. Whenthis final. digit has been dialed, the brushes of connector 250 are positioned on the terminals of the desired line. .Itwill be assumed that station 201 is the desired line and that it is idle; Battery will be found on the sleeve as indicated and a cir- ,cuit WlllqlDQClOSQCl from this battery, brush 280, back contact of release magnet 256, up-

ier windin of relav 251 lower outer back H i i h .i i 7 contact-ofyrclay 252, brush 230, front con tact of armature 205 of relay 206, back contact of: release magnet 209, terminal 151,

brush 150to ground on the upper front contact ofrel ay 113as traced above, thereby fully operating relay 251. The release of relay 252 and operation of relay remove ground 17011) thc'tip of the connect on, there.-

i ill by allowing relay 109 to release and connect ringing current over a circuit from ground on the upper inner back contact of relay 109, upper outer back contact of relay 108, over the tip conductor of the connection to station 201, back over the ring conductor of the allowing it to release. The release of relay 110 opens the ringing circuit but relay 108 does not release as it is locked up through its upper winding to ground on the upper front contact of relay 113. The operation of relay 108 closes the tip and ring conductors from brushes 130 and 140 through to the right hand windings of repeating coil 1'27,

thereby closing a circuit from battery through the lower right winding of repeating coil 127, winding of relay 107, lower outer front contact of relay 108 over the ring conductor through the fifth selector 200 and connector 250, subscribers loop at- 201', back over the tip conductor of the above switches, upper outer front contact of relay 108, upper right winding of repeat coil 127 to ground. Relay 107 operates in this circuit and closes an obvious circuit for relay 111, causing the battery and ground supplied to the wind ing of relay 112 to be reversed back to the first selector 104 for supervisory purposes as is well known to the art.

hen the calling subscriber restores the Hreceiver on the switchhook, the line finder 103, first selector 104, second selector 105 and; third selector 106 release in a manner well known to the art. The release of the first selector 104 opens the circuit for relay 112, thereby releasing relay 113. A circuit is nowclosed from ground on the back contact of relay 112, lower back contact of relay 113, upper alternate contact of off-normal springs 126 to battery through the winding of release magnet 115. The operation of release magnet 115 causes the brushes 130, 140,; and 150 to be restored to normal and all operated relays in this selector released. As the release magnet 115 operates the sleeve circuit through brush 150 is opened, thereby releasingrelay 206 which closes an obvious circuit for release magnet209 from ground on its lower back contact. Release magnet 209 restores the brushes 210, 220 and 2 to normal, thereby releasing relay 251 which now opens the operating circuit for relay cu-it'i-s provided on the release of relay251 as follows: from battery, through the Winding of relay 254, lower'i'nner front contact of'relay 253, upper middle back contact of relay 251, s'ubscribers loop at 201,- upper outer back contact of relay 251to ground on thel'owe-r outer front contact of relay 253. \Vhen relay 254 operates an obvious holding circuit is closed for relay 253, which therefore preventsthe connector 250 froinreleasingto maintain the busy condition on both the sleeve of the connector and thesub scribers line'until the called subscriber hangs up.

When the called subscriber at 201'replaces the receiver on the switchhook, relay 254 will release, thereby releasing relay 253 which closes a circuit forrelease magnet 256 from ground on the lower outer back contacts of relays 253 and 251, upper alternate contact of off-normal spring 255 to battery through the release magnet 256, causing the switch to be restored to normal.

If selector 200 should find during 1ts hunt ing movement that all of the trunks are busy,'the brushes will rotate to the eleventh terminal, at which time the eleventh rotary off-normal springs 221 will be operated to close a circuit from ground through interrupter 222, lower contacts of springs 221, terminal 141, brush 140, lower outer front contact of relay 108, winding of relay 107,

lower right winding of repeating coil 127 to battery. Relay'107 operates and releases in this circuit following interruptions by interrupter 222. The operation ofrelay 107 closes an obvious circuit for relay 111 causing the battery and ground through windings of relay 112 to be reversed, thereby controlling the prior selectors. Tone at 223 is also connected throughthe upper alternate contact of spring 221' to thetip of the conlUU nection for giving thecalling subscriber a busy tone, y Should connector 250 find that the desired line is busy, the same operation is followed using interrupter 263 and tone at 265.

WVhat is claimed is:

1'. In a telephone system, a series of selec tors, a connector, a calling subscribers station, a dial at'said subscribers station, lines not exceeding three conductors each interconnecting said selectors and the connector, and means in a preceding selector under con trol of said dial for controlling the operation of the last selector ofsaid' series andthe' connector over the interconnecting lines;

' 2. In a telephone system, a series' ofsel'ectors, a connector, lines not exceeding three conductors eachinterconnecting said selectors a'ndthe connector, a calling subscribers station, a dial at said subscriber--s station,

all of the selectors except the last in the series being under direct control of said 'rlial,

and means for controlling said last selector and the connector over the interconnecting lines from a preceding selector.

3. In a telephone system, a calling subscribers station including a dial, a called subscribers station, a selector, a second selector, a connector, lines not exceeding three conductors each interconnectingsaid calling station, the selectors, the connector and the called station, said first selector being positioned under control of said dial over the corresponding interconnecting line, a relay in said first selector under control of said dial for controlling the positioning of said second selector and the connector over the respective interconnecting lines, and means in said first selector for connecting ringing current to said called subscribers station through said second selector over the respective interconnecting lines.

4. In a telephone system, a calling subscribers station, a called subscribers station, a series of selectors, a connector, means in one of said selectors for releasing said connector, a sloW-to-release relay in said connector, a second relay in said connector, said firstrelay arranged to close a circuit for said a second relay through the called subscribers station for holding said connector busy until said called subscriber releases.

5. In a telephone system,calling and called lines, a train of automatic switches for interconnecting said lines including a selector, a succeeding selector and a connector, means to position said first selector, circuits in said first selector, means including said circuits to control the operations of said succeeding selector and the connector, means to release said selectors, and means under the control of the called subscriber to release said connector.

6. In a telephone system, calling and called lines, a train of automatic switches for interconnecting said lines including a, selector, a succeeding selector and a connector, means to position said first selector, circuits in said first selector, means including said circuits to control the operations ofsaid succeeding selector and the connector, means to release said selectors, and means under the control of the called subscriber for releasing said connector and for nfiintaining said connector busy until released.

7. In a telephone system, a series of selectors, a connector, a calling subscribers station, a dial at said subscribers station, lines not exceeding three conductors each interconnecting said selectors and the connector, means in a preceding selector responsive to the actuation of'the dial for controlling the operation of the last selector of said series and the connector over the interconnecting lines, means for releasing said selectors, and means for holding said connector busy after said selectors are released.

8. In a telephone system, a series of selectors, a connector, :1 calling subscribers station, a dial at said subscribers station, a called subscribers station, lines not exceedin three conductors each interconnecting said calling station, the selectors, the connector and the called station, means in a preceding selector under control of said dial for controlling the operation of the'last selector of said series and the connector over the interconnecting lines, and means in said preceding selector for connecting ringing current to said called subscribers station through the interconnecting lines.

9. In a telephone system, a calling subscribers line, a dial associated with said line, a called subscribers line, a series of selectors, a connector, means responsive to the actuation of the dial for actuating said selectors and connector to interconnect said lines, a source of ringing current in the next to the In witness whereof, I hereunto subscribe my name this 13th day of July, A. 1)., 1926.

RALPH L. QUASS.

DISCLAIMER 1,660,975.Ralph L. Quass, Hawthorne, N. J. TELEPHONE SYsTEM. Patent dated February 28, 1928. Disclaimer filed January 25, 1930, by the assignee by mesne assignments, Western Electric Company, Incorporated. Hereby enters this disclaimer to the said claims of said Letters Patent which are in the following Words, to Wit:

1. In a telephone system, a series of selectors, a connector, a calling subscriber's station, a dial at said subscribers station, lines not exceeding three conductors each series and the connector over the interconnecting lines.

2. In a telephone system, a series of selectors, a connector, lines not exceeding three conductors each interconnecting said selectors and the connector, a calling subscribers station, a dial at said subscribers station, all of the selectors except the last in the series being under direct control of said dial, and means for controllin said last selector and the connector over the interconnecting lines from a preceding selector.

3. In a telephone system, a calling subscribers station including a dial, a called subscribers station, a selector, a second selector, a connector, lines not exceeding three conductors each interconnecting said calling station, the selectors, the connector and the called station, said first selector being positioned under control of said dial over the corresponding interconnecting line, a relay in said first selector under control of said dial for controlling the positioning of said second selector and the connector over the respective interconnecting lines, and means in said first selector for connecting ringing current to said called subscribers station through said second selector over the respective interconnecting lines.

8. In a telephone system, a series of selectors, a connector, a calling subscribers station, a dial at said subscribers station, a called subscribers station, lines not exceeding three conductors each interconnecting said calling station, the selectors, the connector and the called station, means in a preceding selector under control of said dial for controlling the operation of the last selector of said series and the connector over the interconnecting lines, and means in said preceding selector for connecting ringing current to said called subscribers station through the interconnection lines.

[Oficial Gazette February 11, 1980.] 

